how to add foreign key in laravel migration code example

Example 1: laravel rollback last migration

php artisan migrate:rollback --step=1

Example 2: laravel foreign key

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});
OR
Schema::table('posts', function (Blueprint $table) {
    $table->foreignId('user_id')->constrained();
});

Example 3: foreign key laravel migration

$table->foreign('column_name')->references('id')->on('table_name')->onDelete('cascade');

Example 4: laravel migration foreign key 5.6

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});

Example 5: laravel migration integer

$table->bigInteger('votes');